Aerodynamic separation of gas constituents is useful for a number of industrial and commercial applications. An aerodynamic separation nozzle, or, as used herein, a separation nozzle, uses aerodynamic effects and forces generated by high speed flow through structures to apply large centrifugal and aerodynamic forces to gases flowing through those structures to urge the various gas species that comprise a separation gas to be separated (i.e. process gas) apart thereby enabling separation of the gas species. The combination of the centrifugal forces and the design of the structure are adapted to the type of gas species being separated. In particular, the invention disclosed herein in its various embodiments preferentially separates and isolates the constituents of a process gas into heavier and lighter species that are suitable for concentration and collection. In one aspect the aerodynamic separation nozzle utilizes temperature control of the nozzle to enhance separation efficiency. In another aspect, the aerodynamic separation nozzle utilizes pre-conditioning of the incoming gas stream to enhance separation efficiency. In still other aspects combinations of the foregoing are used to enhance separation efficiency.